Differences in muscarinic-receptor agonist-, oxytocin-, and prostaglandin-induced uterine contractions.
OBJECTIVE
To investigate the contractile response of the perfused swine uterus to various receptor pathways (oxytocin, prostaglandins, and muscarine).


METHODS
An extracorporeal perfusion model of the swine uterus was used that keeps the uterus in a functional condition and is appropriate for the study of physiologic questions.


METHODS
Oxytocin-, prostaglandin-, and carbachol-induced uterine contractility and peristalsis were assessed using an intrauterine double-chip microcatheter.


METHODS
University hospital.


METHODS
Intrauterine pressure profiles.


RESULTS
A dose-dependent increase in intrauterine pressure (IUP) in the isthmus uteri and corpus uteri was observed after the administration of prostaglandin F(2alpha) (PGF(2alpha)) and oxytocin, which reached a plateau after further stimulation. A dose-dependent increase in IUP in the isthmus uteri and corpus uteri was also observed after the administration of prostaglandin E(1) (PGE(1)) and prostaglandin E(2) (PGE(2)), with a plateau in IUP in the middle-concentration range and a decrease during the further course of stimulation. After administration of PGE(1), PGE(2), and PGF(2alpha), different directions of contraction waves were also observed. Carbachol also showed a unique contractility pattern, with isolated, very powerful, dose-dependent contractions with an IUP gradient, suggesting directed transport from the upper region to the lower region.


CONCLUSIONS
This study demonstrated that oxytocin, the prostaglandins, and carbachol modulate contractility in nonpregnant swine uteri in a characteristic way, resulting in different contractility patterns.
Dittrich
Ralf
R
Department of Obstetrics and Gynecology, Erlangen University Hospital, University of Erlangen-Nuremberg, Erlangen, Germany. ralf.dittrich@uk-erlangen.de
Mueller
Andreas
A
Oppelt
Patricia G
PG
Hoffmann
Inge
I
Beckmann
Matthias W
MW
Maltaris
Theodoros
T
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005260:Female; D066298:In Vitro Techniques; D018721:Muscarinic Agonists / Q000494:pharmacology*; D010121:Oxytocin / Q000494:pharmacology*; D010477:Perfusion; D011312:Pressure; D011453:Prostaglandins / Q000494:pharmacology*; D013552:Swine; D013997:Time Factors; D014590:Uterine Contraction / Q000187:drug effects* / Q000502:physiology
D018721:Muscarinic Agonists; D011453:Prostaglandins; D010121:Oxytocin; D002217:Carbachol